Sand plug or safety valve for wells



July l24, 1951 i P. H. GRANBERRY SAND PLUG 0R SAFETY VALVE FOR WELLSFiled May 15, 1949 INVENToR. ,Pwjlranberzy BY Patented July 24, 1.951

UNITED STATES PATENT `OFFKE f 4 l .2,561,980 f SAND PLUG oRsAFETY VALVEFOR WEL-Ls .eat n. 'eranterm De mener, La. h Appelation 'May 13,1949,'ser1a1N0. 93,040

- 1 The present invention vrelates toan improved strainer attachment)for wells.

An important object 'consists in associating with the lower end or aWell strainer or screen tubing, 'a safety valve for insuring a positivesealbeing provided at the bottom of the strainer tubingwhen the latteris inserted in a well and :after the drillingoperation has beencompleted, so as 15o-acquire all liquid introduced intov the tubing tofirst pass through the strainer so as tol remove sand, grit andother'foreign matter therefrom.

Y A vfurther object is to provide a well strainer or tubing with astrainer valve designed to ybe used 'in conjunction with ay conventionalspring pressure valve so as to prevent fluid from passing up through thetubing when the 1atter 1s Abei-ng lowered into a well, rand which alsowill require all water coming into the well to pass throughthe'strainerso as to separate foreign matter from the` Water so thatwhen the drilling mud and fluid washed out of the well by theapplication of v pump pressure at the upper end of the strainer pipe,any 'pebbles or large grainsof sand that might collect or adhere to thebottom of the pressure valve,v and cause it to remain open, will beprevented from passing back inside of the pipe strainer due to the factthat the valve plug will cut off the flow of such supply andwill'require all fluid to pass rst through the strainer before beingIintroduced into the pipe. i

Another object is to provide a sand plug Vor strainer'plug valve Vwithmeans Aso that fluidv under pressure may `be introduced v-into thestrainer tubing, should 'for any `reason sand, sediment or foreignmatter collect at the bottom of'the strainer and resist the-movement ofthe plug valve into sealing engagement with'its seat. InOther objectsand advantages -of the invention will becomeapparent from thefollowingdescription when taken in conjunction with the accom`panyingclaimfancl drawings. I t Referring to the dra-wings in which areshown several preferred embodiments of the invention: Figure 1 is a sideview with parts `in Sectio bf the improved strainer attachment. 'Figurev2 is a detail sectional view taken subi stantially along the line`-2-1! of Figure v'3.

vFigure 3 is anenlarged sectional view taken substantially along theline 3-.3 of Figure l.

Figure 4 is aside elevational view of parts vin section of av modified-form of the invention.

' Figure 5 is asecti'o'nalview taken substantiallyr alongthe line 5--5-of Figure 4. Y

Figure 6 is a sectional view taken substantially along the linefG--fofFiguredl, and '1 1 Ulain. (Cl. 16S-420) Figure 7 is a sectional viewtaken substantially along the line 1 -1 o'f Figure 4.`

Referring to the drawings in which like numeri als indicate `like 'partsin the several views,y 'the strainer attachment includes 4a Well tubing4or pipe t0 (Fig. l) provided in the upper portion thereof with openingsH aroundwhich are preier'ably Wrapped wire l2 to provide a strainer Yforpreventinggritty fluid, sand 'or sediment from being 'introduced fromthe vwell bore 'into the pipe HJ 'when the latter is inserted into awell 'after the v'hydraulic drilling 'operation has been v'cornpl'ete'd.The Ylower end portion off the pipe "IU externally threaded as at I3 soas t'o receivethe complementary internal threads r4 on Vtime 'coin`pling member or sleeve l5. A tubular vbottom member or vnipple lli hasits upper end portion externally threaded as "at I1 so 'as to engage'thethreads on the coupling l5 in order to v:firmly but detachably connect'the strainer pipe il to thev bottom or nipple member i6. A cylindricalclo" sure member or cap I8 (Fig. 2) has its outer periphery externallyvthreaded 'as 'at' IS, and is of such ar diameter as to vbe connected tothe coupling threads hl between the connection 'of the pipe lu andthebottom member 'IB therewith (Fig. '1). The closure member I8 ispreferably formed with an upwardly extending' polygonal shaped reducedportion or head 20 for-receiving a suitable tool, so as to connectorremove the closure I8 from the coupling l5. The plug I8 and the head 2l;are formed with acentrally dis` posed righthand threaded opening llwhich, vat

its upper end, is preferably ared'outwardly as at 22 for ,a purpose'subsequently to 'be described.

r A sand plug valve 23 is arrangedv to be 'insertable in the strainertubing and has a solid lower end portion 24 'which is externallythreaded as at '25 and has its threads ofthe same pitch as the threads2l of the closure member I8. Above the solid portion 24, the plug 2'3hasan axially disposed opening 26 which communicates Witha' transverseor radial through opening 2l adjacent the solidportion 213. The upperend 'of the valve plug 23 has an externally threaded portion 28, thethreads of which are pitched-opposite to that of 'the threads 25 and, asshown,y are left-hand threadsas contrasted to the rightehand threads 25.A hollow rotatable operating rod or pipe 29 (Fig. Y2) is arranged toextend axially `into the Well bore and has vits lower end portionyformed with external threads 30 preferably of rig-hthand pitch. -Acoupling or sleeve 3l arranged to nde't'achably connect theoperatingrod-ZQ tothe valve plug 23 and, fas shown, thecoupling-or-oonnecting member 3I has the bore thereof provided withleft-hand threads 32 in the lower end thereof and with right-handthreads 33 in its upper end. Thus, it will be seen that the couplingmember 3| may be detachably connected to the threads 28 on the plug 23,while the threads 33 of the coupling may be releasably secured to thethreads 33 on the operating rod 23.

As shown, the plug 23 provides a sand plug valve and the closure member'I8 is arranged to be secured to the coupling I5 between the two pipemembers I and I5 (Fig. l), so as to be securely retained in place andcannot be removed after the coupling I is tightened and the partsassembled. The sand plug valve is so constructed and arranged as toinsure a positive seal between the strainer tubing or pipe I3 and thebottom tubular member or nipple I6 when the attachment is inserted in awell that has previously been hydraulically drilled.

In operation, the closure member I8, which constitutes a valve seat, isplaced in lposition on the coupling I5 between the pipe members In andI6 but without the plug valve 23 being connected thereto and while thewell bore is still full of drilling mud. The strainer attachment, asthus assembled, is then lowered in the well until the proper sand isreached. The drilling mud is now washed out of the well by pumping clearwater down into the strainer tubing ID so as to pass through the opening2I in the closure I8 and through the nipple I6. This operation iscontinued until the mud is removed from the sand. Before starting topump the well, the sand plug valve 23 is connected to the operating rod29 by the coupling 3l and is inserted into the well and the strainerpipe I0. When the plug 23 comes in contact with the inclined or taperedside 22 of the closure I8, it will be moved into proper alignment withthe threaded opening 2l so that upon rotating the rod 23 to the right orclockwise, the plug 23 is screwed into the opening or seat 2I and whenthe plug is iirmly tightened, the lefthand threads 28 on the upper endthereof will start to unthread and cause the coupling 3l to back off soas to leave the plug 23 in sealing engagement with its seat on theclosure I8, thus providing a tight seal in the bottom of the well thatwill require all water coming into the strainer to rst be strained andremoved from the sand, sediment or other foreign matter by passingbetween the wire I2 and through the openings II before being introducedinto the tubing I0.

The Valve plug 23 is formed with the axial passage 2B and the branchpassage 21 so that in case sand or sediment collects in the bottom ofthe strainer sufficiently to resist the plug being moved downwardly intoengagement with its seat on the closure member I8, means are providedwhereby water or air may be pumped down into the strainer tubing so asto wash away the sand or sediment and thus allow the valve 23 to beseated on the closure i8 so as to seal the well. v

In the modied forms of the invention dis` closed in Figures 4 and 5, thestrainer is substantially similar to that previousl;7 describedyand hasassociated with it a conventional'spring pressure valve. As shown, thestrainer tubing or pipe 34 is connected to a tubular bottom. member ornipple 35 by a coupling 35 which is interiorly threaded as at 31 toreceive the complementary threaded end portions 33 and 39 on the pipe 34and tubular member 35, respectively. A cylindrical closure member or cap4I? is externally threadedvas at 4|`V so as to engage. AthethreadsT 75ascisse f 4 on the coupling 36 when the parts are assembled. The closuremember 4|] is provided with an upwardly extending boss or reduced`portion 42 and has a central through opennig 43, the upper wall ofwhich is provided with right-hand threads 44 (Fig. 5) arranged toreceive the complementary formed threads 45 on the lower solid portion46 of the plug valve 41. The upper wall of the opening 43 is preferablyflared as at 48 and the lower end portion of the Wall 43 may besimilarly flared as at 49 so as to terminate in the enlarged annularportion 50. The valve plug 41 is formed with the axial passage 5I andthe branch radial Ipassage 52 which are positioned above the solidportion 4E. A tubular operating rod 53 is detachably connected to thesafety valve 41 by the coupling or sleeve 54, the bore of which has alower left-hand threaded portion 55 engaging the complementary threadedportion of the valve 41. The upper threaded portion 56 of the couplingbore has right-hand threads which engage complementary threads 51 on thelower end of the rod 53, so that the strainer Valve 41 may be con-'-nected and permanently secured to the closure plug 40 in substantiallythe same manner as the sand plug valve 23 previously described.

The closure member 40 has a transverse bottom web 58 (Fig. 7) extendingacrossthe en -l larged opening 5,5 and provided with a central threadedopening 59 (Fig. 5) which receives a threaded bolt 6U. A displaceableclosure disk or member 6I has the bolts 6l] extending centrallytherethrough and is arranged to be yieldafb'ly urged against the bottomof the member 4U to close theopening 5I) by a coil spring 62 connnedbetween the disk El and the head 63 of the bolt 50. I t, will be seenthat the disk` 6I constitutes aspring pressure valve associated with thestrain l ernvalve 41k so'that when the strainer is use' theufluidcannotulo'w up fast into andthrougl thestring of tubing 34 when theattachment being lowered or inserted into the Well. In operation, afterhole is full of mud and the depth ofwater bear'lf ing strata isdetermined, the closure meinber 40 is connected'tothe coupling sleeve 36adjacent"v the bottom of theY strainer and sufficient 'pipe'zis attachedto the upperend of the strainerfso" that" the string of tubing may belowered into the well until the strainer reaches the water bearingstrata. The/spring pressure valve 6 i will now operateto close theAopening 50, and'preclude the water or fluid passing up vvfrom 'the'nipple 35 into the pipe 34 'during the lowering; operation. Fresh wateris 'now pumped into"t`h'e tubing fromthe vupper end thereofuntilallf'rnud is Washedout from inside of the Ipipe andbacked up on theoutside of the pipe adjacent the bottom ofthe well. yAfter this washingoperation iscolmypleted and the well is ready to produceoil or; Water,plug valve A41is connected through Vthe coupling 54 with the tubularoperating rod53 'and' is introduced into `theuweil sothat clockwisenro;tation causes the threads 44 on the lower solid portion 46 of the valveto be broughtuand main; tained in y rm sealing engagement with thethreads onvthe wall of the valve seat opening 4 3).M .Continued rotationY0f the operating, member 29 and the valve plug 41 in this directionwill ref-L lease the threaded engagement of the coupling 54 with thevalve 41, so that thecoupling iriay.l be v*moved baclroff of .thevalvewithout disturbing the tight sealing engagementof the plugwith, itsvalveseat n will be seenthatthesprine presentaran.,

the well is drilled and the" l 5 e El, when associated with the strainervalve 41, will insure a positive seal being provided and will precludepebbles, shale or sand from interfering with the closing of the valve 6|which heretofore has interfered with the eicient operation of valves ofthis type.

The plug valves 23 and 41, it will be observed, are not initiallypositioned within the strainer tubing and each has a solid lower stemportion movable into sealing engagement with its valve seat, so as toremain in this closed position and cut oi the upward ow of the liquidinto the strainer above the closure member 20 or 40. In other words, theplug valve is substantially different in construction and operation fromthe hollow stem type of well valve that is opened and closed by a portthrough the center and which, when the port is moved above the seat,opens the valve while closing the same when the port is moved below theseat. The upwardly and outwardly flared portions of the closure membersI8 and 20 constitute guide means for insuring their associated plugvalves being properly moved into threaded engagement with the seatopenings rso as to facilitate the eicient operation of the valveassembly. This valve can be used as an additional safety factor inconjunction with ball-type oating check valves or spring valves.

It ywill be understood that the forms of the invention shown anddescribed are merely illustrative of preferred embodiments and that suchchanges may be made as fall within the scope of the following claim.

I claim:

Astrainer attachment yfor wells including a tubing having straineropenings in the wall thereof, a closure member connected to the bottomof the tubing and having a centrally disposed threaded opening forming avalve seat, a plug valve insertable in said tubing for engagingpermanently said valve seat, said plug valve having a solid lower endportion provided with external threads pitched in the same direction asthe threads in said central opening, said plug having an axial passageabove the solid portion and extending to the opposite end thereof and atransverse passage above the solid portion communivsaid transversepassage, and a coupling sleeve having its bore provided with a lowerthreaded portion having the same pitch as the externall threads on theupper portion of said plug, the upper end portion of said bore havingthreads pitched opposite to the threads on the lowerr end portion of thebore, and a tubular rotatable operating rod insertable axially into saidtubing, said rod having an externally threaded lower end portionprovided with threads of the same pitch as the threads on the upper endportion of the coupling so as to engage the same, the parts beingconstructed and arranged so that upon inserting the rod with the plugconnected to the lower end thereof through the coupling sleeve into thetubing and rotating and moving the rod axially, the plug is brought intothreaded engagement with the valve seat opening in the closure memberand upon continued rotation in the same direction the plug is forcedinto permanent sealing engagement with the valve seat while the threadedconnection of the plug with the rod is simultaneously unthreaded todisconnect the coupling from the plug so that the latter provides anunremovable i seal at the bottom of the well and requires all watercoming into the tubing to vpass first through the strainer openings, thepassages in said plug providing means for introducing fluid underpressure into the strainer attachment so as to remove any sand orsediment that collects in the strainer and would resist the insertion ofthe plug valve into sealing engagement with its seat.

PAT H. GRAN BERRY.

REFERENCES CITED The following vreferences are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,594,303 Keown et al July 27,1926 1,596,260 Thomson Aug. 17, 1926 1,685,971 Adams Oct. 2, 19281,810,757 Cunningham June 16, 1931

